title: A model for the study of diffusion and perfusion limitation.
abstract: On the basis of a very simple model for the association of diffusion and perfusion, an association common to many respiratory gas transfers, a simple equation is described that defines gas partial pressure equilibration in diffusion-perfusion-limited systems as a function of the ratio of D to beta bQ(D = diffusing capacity, beta b = blood capacitance coefficient, Q = perfusion). The equation applies to steady-state conditions and assumes D, beta b, and Q to be independent of gas partial pressures. In spite of the fact that this assumption may represent a gross simplification, the equation can be regarded as a powerful conceptual tool in the analysis of most gas exchange systems.
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D008433:Mathematics; D008954:Models, Biological; D010100:Oxygen / Q000502:physiology; D010313:Partial Pressure; D011653:Pulmonary Diffusing Capacity; D014692:Ventilation-Perfusion Ratio
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen